Spiders that are attracted to the smell of petrol have forced Mazda Motor Corp to recall a line of its saloons in North America.
The creatures caused the problem by weaving webs that block a vent in the engines. Mazda has since alerted US regulators that it is recalling 42,000 Mazda6 sedans with 2.5 litre engines from model years 2010 to 2012.
Mazda officials were not immediately available to report recalls outside of the United States.
The company’s admission comes three years after spiders caused the same problem in Mazda6 sedans in North America from model years 2009 and 2010, after their webs blocked evaporative canister vent lines.
At the time, the company recalled 65,000 of the cars. Mazda tried to fix the problem by adding a spring to the canister vent line to keep spiders from crawling inside.
While the method worked for the most part, Mazda received several reports of cracked fuel tanks in sedans equipped with the spring and the firm’s engineers tried to figure out the spider's route to the canister.
The spider's webs can restrict the flow of fuel, which in turn can reduce fuel tank pressure when the emission control system purges vapors from the evaporative canister.
This can put stress on the fuel tank, which may crack and leak fuel, increasing the risk of a fire, a report filed with National Highway Traffic Safety Administration said.
Mazda said it is not aware of any fires because of this risk.
After learning of nine cases in which tanks were damaged even though a spring was loaded, engineers said that a change in the car's software would keep tanks from cracking even if a spider web blocks a vent.
Mazda will inform owners in the recall campaign to bring cars to dealers, where the evaporative canister vent line will be checked and cleared if necessary. Dealerships will also reprogram software.
The blockage is not present on other models made by Mazda and occurs only in cars made a plant in Flat Rock, Michigan, at which Mazda once produced cars jointly with Ford Motor Co.
Mazda stopped production of cars at Flat Rock in August 2012.
Additional reporting by Reuters